Final answer:
Signal turn indicators are required on motor vehicles when the body or load of the vehicle extends to the left of the center of the steering wheel. This requirement is based on traffic laws and regulations that aim to ensure safe and efficient driving.
Step-by-step explanation:
In many countries, including the United States, signal turn indicators are required on motor vehicles when the body or load of the vehicle extends to the left of the center of the steering wheel. This requirement is based on traffic laws and regulations that aim to ensure safe and efficient driving.
Signal turn indicators, also known as blinkers or indicators, are electrical devices that are mounted on the front and rear of vehicles. When activated by the driver, they emit a blinking light to signal their intention to turn left or right, helping other drivers and pedestrians anticipate their movements.
For example, if a truck is carrying a wide load that extends to the left side of the vehicle, drivers behind the truck may not be able to see any hand signals made by the driver. In such cases, the use of turn indicators becomes crucial for indicating lane changes and turns.